Skip to content

Author: Sima

Published on Leave a comment on American Academy of Pediatrics: End Routine Antibiotic Use in Animals

The American Academy of Pediatrics released a new report that the overuse of antibiotics in animals poses a real health risk to children. Giving routine antibiotics to animals leads to antibiotic resistant bacteria  - which means that antibiotics may not work when given to people. Most of the antibiotics sold in the U.S. each year - 80 percent- are used in animals that people than eat. The great majority of antibiotics given to animals are the same ones given to humans.The main way to ensure that the meat that you are purchasing is antibiotic-free is to buy meat labeled organic. And to buy organic dairy products (milk, butter, cheese, cream). Note that the reason routine use of antibiotics in animals has not been stopped so far in the USA is due to agriculture industry lobbying. From Medical Xpress:

Pediatricians' group urges cuts in antibiotic use in livestock

Overuse of antibiotics in farm animals poses a real health risk to children, the American Academy of Pediatrics warns in a new report.This common practice is already contributing to bacterial resistance to medicines and affecting doctors' ability to treat life-threatening infections in kids, according to the paper published online Nov. 16 in the journal Pediatrics.

"The connection between production uses of antibiotics in the agricultural sector to antibiotic resistance is alarming," said Victoria Richards, an associate professor of medical sciences at the Quinnipiac University School of Medicine in Hamden, Conn. She believes the danger is "not only for infants and children but other vulnerable populations, such as the pregnant and the older individuals."

As the academy explained in its warning, antibiotics are often added to the feed of healthy livestock to boost growth, increase feed efficiency or prevent disease. However, the practice can also make antibiotics ineffective when they are needed to treat infections in people. Some examples of emerging antibiotic germs include methicillin-resistant staphylococcus aureus (MRSA), C.difficile, and highly resistant strains of the tuberculosis bacterium. Each year, more than 2 million Americans develop antibiotic-resistant infections and more than 23,000 die from these infections, the academy said. And in 2013, the highest incidence of such infections was among children younger than 5, federal government statistics show. 

"Children can be exposed to multiple-drug resistant bacteria, which are extremely difficult to treat if they cause an infection, through contact with animals given antibiotics and through consuming the meat of those animals," report author Dr. Jerome Paulson, immediate past chair of the academy's executive committee of the Council on Environmental Health, said in an academy news release."Like humans, farm animals should receive appropriate antibiotics for bacterial infections," he said. "However, the indiscriminate use of antibiotics without a prescription or the input of a veterinarian puts the health of children at risk."

Spaeth noted that the U.S. Centers for Disease Control and Prevention, as well as the World Health Organization, have both called for a curbing of antibiotic use in animals. But the authors of the new report expressed concern over resistance from the agriculture and farming industry to such measures.

Published on Leave a comment on Which Mosquito Repellents Work?

People spend a lot of effort trying to repel mosquitos  - because the bites are so annoying and because they spread serious diseases. New research looking at different mosquito repellents - both DEET and non-Deet ("natural") products - had interesting results. What was once thought effective in repelling mosquitoes doesn't work at all (vitamin B patch), and what was thought attractive to mosquitoes may actually repel them (floral scents), and the "natural" alternatives may or may not work. Also - the species of mosquito is important (they tested Aedes aegypti and Aedes albopictus), for they found that there was some variation among the 2 species in what they were attracted to or repelled by. Best choices for protection lasting at least 2 hours: DEET repellants, Cutter lemon eucalyptus insect repellent, and Victoria's Secret Bombshell. Best protection lasting 4 hours: DEET repellants, and Cutter lemon eucalyptus insect repellent. This last non-DEET product contained lemon-eucalyptus oil containing p-menthane-3,8-diol. Of course there was an untreated control (an attractive to mosquitoes volunteer's bare hand) in the study for comparison purposes.

However, while EcoSmart organic insect repellent  worked for 4 hours for Ae. albopictus mosquitoes, it only worked for the first few minutes for Ae. aegypti mosquitoes (so don't buy this product). For years people thought that Avon Skin So Soft worked well as a repellent - well, forget it- not good at all. Other products that did not work: a mosquito skin patch (vitamin B), and Cutter natural insect repellent. These results showed that DEET-free products containing citronella or geraniol did not work. See the original study for the result lists for 10 products for both species of mosquitoes. From Popular Science:

VICTORIA’S SECRET PERFUME WARDS OFF MOSQUITOES, STUDY FINDS

Because mosquitoes carry diseases like malaria and dengue fever, and irritate us, humans do a lot to avoid them. In most places people have to fend for themselves against the pests by sleeping under mosquito nets or using repellant. A number of new repellant formulas have hit the market in recent years, many with questionable efficacy. Researchers at New Mexico State University decided to compare the effectiveness of different repellants and perfumes, according to a study published recently in the Journal of Insect Science.

The Y-shaped tube used in the study.  Rodriguez et al, Journal of Insect Science, 2015

The researchers tested eight commercially available repellents, two fragrances, and a vitamin B patch that reportedly keeps the mosquitoes at bay, on two different species of disease-carrying mosquitoes. To test the efficacy of each, the researchers put a mosquito at the long end of a Y-shaped plastic tube. One of the researchers who is particularly attractive to mosquitoes placed her two hands at the ends of both forked tubes—one hand was untreated, the other treated with the chemical being tested. If the mosquito avoided the tube with the treated hand by staying still or moving towards the untreated hand, the researchers determined that the repellent worked.

The researchers found that, among repellents, those that contained the tried-and-true ingredient DEET were most effective in warding off the mosquitoes. A few others, such as Cutter Lemon Eucalyptus Insect Repellent, worked almost as well, while most of them (including the vitamin patch) didn’t make any difference.

While those findings weren’t unexpected, the researchers were surprised to find that Avon Skin So Soft Bath Oil repelled the mosquitoes for about two hours. Another fragrance, Victoria’s Secret Bombshell perfume, also repelled the mosquitoes and lasted even longer.

That overturned the previous understanding about how mosquitoes interpret scents. “There was some previous literature that said fruity, floral scents attracted mosquitoes, and to not wear those,” said Stacy Rodriguez, a research assistant involved in the study, said in a statement. “It was interesting to see that the mosquitoes weren’t actually attracted to the person that was wearing the Victoria’s Secret perfume – they were repelled by it.”

Published on Leave a comment on Garlic Eating Men Smell More Attractive?

This study found that men who eat a lot of garlic (4 cloves in raw or capsule form) had a "more attractive" body odor to women. This is body odor, which is different than breath odor. Since this study was done in Prague (capital of the Czech Republic), one wonders about cultural biases - is this a group that normally enjoys garlicky foods? What would women who never ate foods containing garlic think about the body odor? The researchers gave an evolutionary explanation, but...first this study needs to be replicated in a group that doesn't normally eat garlic. At any rate, the study results should give reassurance to those men who enjoy eating garlic - it's attractive to women! From Medical Xpress:

Research finds men who eat garlic smell more attractive

The beneficial health properties of garlic are well known, but researchers at the University of Stirling and Charles University in Prague have uncovered another less well known and surprising property – that the body odour of men who eat garlic is attractive to women. In a study of 42 men – who each were asked to eat raw garlic, garlic capsules, or no garlic – their body odour was perceived to be 'significantly more attractive' when they had eaten garlic in bulb and capsule form than when they hadn't eaten it.

For the study, 82 women were asked to sniff the odour samples and judge them on their pleasantness, attractiveness, masculinity and intensity. Researchers found the unexpected positive effect was only achieved once the men were eating a substantial amount of garlic. When the men ate 6g of garlic, equivalent to two cloves, with bread and cheese, there was no difference in the ratings between then and when they simply ate the bread and cheese on its own. 

But when the dosage was doubled to 12g, or four cloves, the men were reported to smell more attractive than when they hadn't eaten it. In the final experiment, when the men consumed the same amount of garlic, but in capsule form, their body odour was also perceived as more attractive.

Craig Roberts, Professor of Psychology at the University of Stirling, said: "Our results indicate that garlic consumption may have positive effects on the pleasure derived from perceived body odour perhaps due to its health effects....Previous research indicates that many animal species use diet-associated cues to select mates in good physical condition. "As the health benefits of garlic consumption include antioxidant, immunostimulant, cardiovascular, bactericidal and anti-cancer effects, it is plausible that human odour preferences have been shaped by sexual selection.

The study concludes that body odour, in contrast to breath odour, is positively affected by garlic and that these two sources of odour should be strictly differentiated. As breath odour plays an important factor in intimate relationships further studies may be carried out.

Published on Leave a comment on One Course of Antibiotics And Your Microbes

New research found that one course of antibiotics (ciprofloxacin, clindamycin, amoxicillin or minocycline) had varying effects on the gut and saliva microbes, with ciprofloxacin having a negative and disruptive effect on gut microbiome diversity up to 12 months. While the microscopic communities living in the mouth rebound quickly, just one course of antibiotics can disrupt the gut microbiome for months - with amoxicillin the least and ciprofloxacin the most (up to a year).The researchers stressed that for these reasons "antibiotics should only be used when really, really necessary. Even a single antibiotic treatment in healthy individuals contributes to the risk of resistance development and leads to long-lasting detrimental shifts in the gut microbiome."

The scary part is that Americans typically take many courses of antibiotics throughout life. And people with conditions such as chronic sinusitis typically take many more than average. From Medical Xpress:

One course of antibiotics can affect diversity of microorganisms in the gut

A single course of antibiotics has enough strength to disrupt the normal makeup of microorganisms in the gut for as long as a year, potentially leading to antibiotic resistance, European researchers reported this week in mBio, an online open-access journal of the American Society for Microbiology. In a study of 66 healthy adults prescribed different antibiotics, the drugs were found to enrich genes associated with antibiotic resistance and to severely affect microbial diversity in the gut for months after exposure. By contrast, microorganisms in the saliva showed signs of recovery in as little as few weeks.

The microorganisms in study participants' feces were severely affected by most antibiotics for months, said lead study author Egija Zaura, PhD, an associate professor in oral microbial ecology at the Academic Centre for Dentistry in Amsterdam, the Netherlands. In particular, researchers saw a decline in the abundance of health-associated species that produce butyrate, a substance that inhibits inflammation, cancer formation and stress in the gut.

"My message would be that antibiotics should only be used when really, really necessary," Zaura said. "Even a single antibiotic treatment in healthy individuals contributes to the risk of resistance development and leads to long-lasting detrimental shifts in the gut microbiome."

It's not clear why the oral cavity returns to normal sooner than the gut, Zaura said, but it could be because the gut is exposed to a longer period of antibiotics. Another possibility, she said, is that the oral cavity is intrinsically more resilient toward stress because it is exposed to different stressors every day.

The investigators enrolled healthy adult volunteers from the United Kingdom and Sweden. Participants were randomly assigned to receive a full course of one of four antibiotics (ciprofloxacin, clindamycin, amoxicillin or minocycline) or a placebo. The researchers, who did not know which medication participants took, collected fecal and saliva samples from the participants at the start of the study; immediately after taking the study drugs; and one, two, four and 12 months after finishing the medications....

Researchers found that participants from the United Kingdom started the study with more antibiotic resistance than did the participants from Sweden, which could result from cultural differences. There has been a significant decline in antibiotic use in Sweden over the last two decades, Zaura said.

In addition, fecal microbiome diversity was significantly reduced for up to four months in participants taking clindamycin and up to 12 months in those taking ciprofloxacin, though those drugs only altered the oral cavity microbiome up to one week after drug exposure. Exposure to amoxicillin had no significant effect on microbiome diversity in either the gut or oral cavity but was associated with the greatest number of antibiotic-resistant genes.

Gut bacteria. Credit: Med. Mic. Sciences Cardiff Univ, Wellcome Images

Published on Leave a comment on Very Low Levels of Vitamin D and Heart Problems

New research found that negative health effects - 35% increased risk of cardiovascular problems (coronary heart disease, heart attacks, strokes) are when the vitamin D levels are really low (under 15 nanograms per milliliter). Currently many doctors recommend optimal levels for health as somewhere between 35 to 40 ng/ml. One article in Medscape recommended 1,000 IU of vitamin D (preferably D3) daily to achieve this level. Or you can go outside in the sun for 15 to 20 minutes. From Science Daily:

Specific vitamin D levels linked to heart problems

A lack of vitamin D can result in weak bones. Recent studies also show that vitamin D deficiency is linked to more serious health risks such as coronary artery disease, heart attacks, and strokes. And now, a new study shows what level of deficiency puts someone at risk of developing these heart problems.Researchers at the Intermountain Medical Center Heart Institute in Salt Lake City have found that patients are fine from a heart standpoint, and may need no further treatment, if their vitamin D level is anywhere above 15 nanograms per milliliter.

"Although vitamin D levels above 30 were traditionally considered to be normal, more recently, some researchers have proposed that anything above 15 was a safe level. But the numbers hadn't been backed up with research until now," said J. Brent Muhlestein, MD, co-director of cardiovascular research at the Intermountain Medical Center Heart Institute, and lead researcher of the study.

The body naturally produces vitamin D as a result of exposure to the sun, and it's also found in a few foods -- including fish, fish liver oils, and egg yolks as well as some dairy and grain products. Those who don't have enough exposure to sunlight or vitamin D producing foods often have low vitamin D levels. Low levels are also attributed to race because people with dark skin have a natural protectant against ultraviolet light.

Dr. Muhlestein and his team have studied the effects of vitamin D on the heart for several years, looking at smaller numbers of patients. In this study, thanks to Intermountain Healthcare's vast clinical database, they were able to evaluate the impact of vitamin D levels on more than 230,000 patients. The 230,000 patients were split up into four groups (<15 ng/ml, 15-29, 30-44, ≥45) and were followed for the next three years by researchers who looked for major adverse cardiac events, including death, coronary artery disease, heart attacks, stroke, and incidents of heart or kidney failure.

Dr. Muhlestein found that for the nine percent of patients in the lower than 15 group, their risk of cardiovascular events increased by 35 percent compared to the other three groups, and the risks faced by the other three groups weren't very different from each other.

Published on Leave a comment on House Dust Contains a Microhistory of Our Life

Nice update from a large crowd sourced study I posted about September 1, 2015. Main finding: all our homes are teaming with microorganisms, which vary according to sex of occupants, pets, geographical location and humidity. In total, the indoor dust contained more than sixty-three thousand species of fungi and a hundred and sixteen thousand species of bacteria. The scientists have posted it all online and members of the public can download the complete data set and hunt for new correlations and patterns. Just remember that all these microbes in our lives is completely normal, and many species are important partners in maintaining our health. Excerpts from Emily Anthes's article in the New Yorker:

Our Dust, Ourselves

Dust talks. That clump of gray fuzz hiding under the couch may look dull, but it contains multitudes: tiny errant crumbs of toast, microscopic fibres from a winter coat, fragments of dead leaves, dog dander, sidewalk grit, sloughed-off skin cells, grime-loving bacteria. “Each bit of dust is a microhistory of your life,” Rob Dunn, a biologist at North Carolina State University, told me recently. For the past four years, Dunn and two of his colleagues—Noah Fierer, a microbial ecologist at the University of Colorado Boulder, and Holly Menninger, the director of public science at N.C. State—have been deciphering these histories, investigating the microorganisms in our dust and how their lives are intertwined with our own.  ...continue reading "House Dust Contains a Microhistory of Our Life"

Published on

Could this be? Fungal infection being the cause of Alzheimer's disease? Noteworthy from a recent study conducted in Spain: all the Alzheimer's disease (AD) patients had evidence of fungal infections in their brains, central nervous systems, and vascular systems, but none were found in the control subjects (those without Alzheimer's disease). Many of the symptoms of AD (such as inflammation of the central nervous system and activation of the immune system) match those with long-lasting fungal infections. A "microbial cause" has long been suggested as a cause of AD, and interestingly other studies have also found fungal infections in AD patients. The research so far has found several fungal species in AD patients (including Candida albicans). The researchers mention that in one study anti-fungal treatment reversed clinical symptoms of AD in 2 patients (but it was written off  as misdiagnosis).

Another possibility that immediately occurs to  explain the findings is that perhaps Alzheimer's disease somehow results in fungal infections - that the AD makes them more prone to fungal infection. In case you're wondering - all the AD patients and control patients studied had died - this is why their brain tissue could be studied so thoroughly. Excerpts from a research article by D. Pisa et al in Nature:

Different Brain Regions are Infected with Fungi in Alzheimer’s Disease

The possibility that Alzheimer’s disease (AD) has a microbial aetiology has been proposed by several researchers. Here, we provide evidence that tissue from the central nervous system (CNS) of AD patients contain fungal cells and hyphae. Fungal material can be detected both intra- and extracellularly using specific antibodies against several fungi. Different brain regions including external frontal cortex, cerebellar hemisphere, entorhinal cortex/hippocampus and choroid plexus contain fungal material, which is absent in brain tissue from control individuals. Analysis of brain sections from ten additional AD patients reveals that all are infected with fungi. Fungal infection is also observed in blood vessels, which may explain the vascular pathology frequently detected in AD patients. Sequencing of fungal DNA extracted from frozen CNS samples identifies several fungal species. Collectively, our findings provide compelling evidence for the existence of fungal infection in the CNS from AD patients, but not in control individuals.  ...continue reading "Fungal Infections Involved in Alzheimer’s Disease?"

Published on Leave a comment on Nonprescription Cold Meds That Don’t Work

When suffering from cold symptoms or acute sinusitis, there are some products that work for nasal congestion, and thick phlegm and mucus. Mucinex works well for thick phlegm and mucus, and Sudafed containing pseudoephedrine works for nasal congestion. However, that Sudafed is behind the pharmacy counter, can only be bought in limited quantities, and one must show a driver's license and sign for it before getting any. There are also many other easily available nonprescription cold products containing phenylephrine. But this latest research shows clearly that products containing phenylephrine don't work at any dose. Bottom line: when buying a decongestant, get the stuff containing pseudoephedrine that is behind the pharmacy counter. From Forbes:

The Popular Over-The-Counter Cold Medicine That Science Says Doesn't Work

The market for over-the-counter cold medicines is worth $8 billion annually, with a hefty portion of that amount spent on drugs marketed as decongestants....According to University of Florida researchers, the oral decongestant phenylephrine simply doesn’t work at the FDA-approved amount found in popular non-prescription brands, and it may not even work at much higher doses. Their conclusions were presented in an editorial in The Journal of Allergy and Clinical Immunology: In Practice....

The study of 539 adults lasted one week and failed to find a dose of phenylephrine within the 10 mg to 40 mg range that was more effective than a placebo in relieving nasal congestion. The approved Food and Drug Administration (FDA) dose is 10 mg every four hours for “temporary relief of nasal congestion.” Consequently, the UF researchers are asking the FDA to remove oral phenylephrine from the market.

“We think the evidence supports that phenylephrine’s status as a safe and effective over-the-counter product should be changed,” said Randy Hatton, Pharm.D., a clinical professor of pharmacotherapy and translational research. “We are looking out for the consumer, and he or she needs to know that science says that oral phenylephrine does not work for the majority of people.”

Back before methamphetamine cooks started buying up non-prescription decongestants to brew crank, all of us were able to buy effective decongestants right off the store shelf without a problem. The active ingredient in those meds, coveted by meth smurfers and cold sufferers alike, was pseudoephedrine. But then federal legislation was enacted to restrict the sale of pseudoephedrine-containing products (Combat Methamphetamine Epidemic Act of 2005) and they were moved behind the pharmacy counter. You can still buy them, assuming you know they’re available, by presenting identification and signing a statement saying you’re not buying the drugs for nefarious purposes.

To fill the store-shelf void, drug companies substituted the already-FDA approved ingredient phenylephrine for pseudoephedrine. Several studies testing phenylephrine against a placebo produced results that question its effectiveness, and eventually the FDA started to at least listen to critics in the research community asking for greater scrutiny. The latest research adds a boldface exclamation point to the criticism. Whether the FDA will choose to act on the findings is another matter, but the science is there.

The number of brands containing phenylephrine are too many to list, but the majority of on-the-shelf oral decongestants list it as an active ingredient, including many multi-symptom products. Instead of buying products containing phenylephrine, the researchers suggest cold and allergy sufferers choose a pseudoephedrine product from behind the counter or nasal steroids for allergic rhinitis.

Published on Leave a comment on Little Is Known About the Viruses Living On Healthy Skin

The microbes living on healthy human skin include bacteria, fungi, and viruses...but 90% of the viruses found on healthy skin in this study are unknown to researchers - thus "viral "dark matter". The skin virome  is the population of viruses on the skin. It turns out that most of the viruses on healthy skin are phage viruses. called bacteriophages.They infect bacteria and may take up residence within bacteria. From Science Daily:

90 percent of skin-based viruses represent viral 'dark matter,' scientists reveal

Scientists in recent years have made great progress in characterizing the bacterial population that normally lives on human skin and contributes to health and disease. Now researchers from the Perelman School of Medicine at the University of Pennsylvania have used state-of-the-art techniques to survey the skin's virus population, or "virome." The study, published in the online journal mBio last month, reveals that most DNA viruses on healthy human skin are viral "dark matter" that have never been described before. The research also includes the development of a set of virome analysis tools that are now available to researchers for further investigations.

Researchers and the public are increasingly aware that microbes living on and inside us -- our "microbiomes" -- can be crucial in maintaining good health, or in causing disease. Skin-resident bacteria are no exception. Ideally they help ward off harmful infections, and maintain proper skin immunity and wound-healing, but under certain circumstances they can do the opposite.

"Until now, relatively little work has been done in this area, in part because of the technical challenges involved. For example, a skin swab taken for analysis will contain mostly human and bacterial DNA, and only a tiny amount of viral genetic material -- the proverbial needles in the haystack." 

Their analysis of samples from 16 healthy individuals revealed some results that were expected. The most abundant skin-cell infecting virus was human papilloma virus, which causes common warts and has been linked to skin cancers. However, most of the detected DNA from the VLPs did not match viral genes in existing databases. "More than 90 percent was what we call viral dark matter -- it had features of viral genetic material but no taxonomic classification," Grice said. That came as a surprise, although of course it highlighted the importance of mapping this unexplored territory.

The findings also clearly linked the skin virome to the skin microbiome: Most of the detected viral DNA appeared to belong to phage viruses, which infect and often take up long-term residence within bacteria. And when Grice and colleagues sequenced skin bacterial DNA from the same 16 subjects, they found that it often contained tell-tale marks -- called CRISPR spacers -- of prior invasion by the same phage viruses.

The results also showed that the skin virome varies considerably depending on the body site. Grice's team took swabs from the palm, the forehead, the armpit, the navel, and other sites, and found, for example, that the virome was most diverse in the crook of the arm, a site that is intermittently exposed and occluded.

Published on Leave a comment on Exposure to Animals In First Year of Life and Lower Risk of Asthma

Labrador Retriever image Other studies have found this same association - that living with a dog or farm animal has health benefits such as lower risk of allergies and asthma. In a Swedish nationwide study looking at over a million children, the association between early exposure to dogs and farm animals and the risk of asthma was evaluated. All children born in Sweden from January 1, 2001, to December 31, 2010 were included. The researchers found that exposure to dogs and farm animals during the first year of life reduces the risk of asthma in children at age 6 years. From Science Daily:

Early contact with dogs linked to lower risk of asthma

A team of Swedish scientists have used national register information in more than one million Swedish children to study the association of early life contact with dogs and subsequent development of asthma. This question has been studied extensively previously, but conclusive findings have been lacking. The new study showed that children who grew up with dogs had about 15 percent less asthma than children without dogs.

A total of more than one million children were included in the researchers' study linking together nine different national data sources, including two dog ownership registers not previously used for medical research...."Earlier studies have shown that growing up on a farm reduces a child's risk of asthma to about half. We wanted to see if this relationship also was true also for children growing up with dogs in their homes. Our results confirmed the farming effect, and we also saw that children who grew up with dogs had about 15 percent less asthma than children without dogs.

"These kind of epidemiological studies look for associations in large populations but do not provide answers on whether and how animals could protect children from developing asthma. We know that children with established allergy to cats or dogs should avoid them, but our results also indicate that children who grow up with dogs have reduced risks of asthma later in life. Thanks to the population-based design, our results are generalizable to the Swedish population, and probably also to other European populations with similar culture regarding pet ownership and farming" says Catarina Almqvist Malmros, senior author on the study, Paediatrician at Astrid Lindgren Children's Hospital and Professor in Clinical epidemiology at Dept of Medical Epidemiology and Biostatistics at Karolinska Institutet, Stockholm.